The invention relates to the lighting arts. It is especially applicable to MR/PAR-type lamps and lighting systems, and will be described with particular reference thereto. However, the invention will also find application in modular lighting, in portable lighting applications such as flashlights, in retrofitting incandescent and other types of lamps with LED-based lamps, in computerized stage or studio lighting applications, and the like.
MR/PAR-type lamps usually refer to incandescent lamps having an integrated directional reflector and optional integrated cover lens for producing a directed light beam with a selected beam spread, such as a spot beam or a flood beam. The integral reflector is typically of the mirrored reflector (MR) type which uses a dichroic glass reflector material, or of the parabolic aluminized reflector (PAR) type. The choice of reflector affects the heat distribution, spot size, lamp efficiency, and other properties. MR/PAR lamps are available in a wide range of reflector sizes, typically indicated in multiples of xe2x85x9th inch. For example, a lamp designated as PAR-16 has a parabolic reflector with a diameter of two inches. In the art, the terms MR lamp, PAR lamp, MR/PAR lamp, and the like typically denote a directional lamp having a standardized size, shape, and electrical connector. Commercial MR/PAR lamps are manufactured and sold as an integrated unit including an incandescent light source, a reflector that cooperates with the light source to produce a beam having a selected beam spread such as a spot beam or a flood beam, and a standardized base with an integrated standardized electrical connector which often also provides mechanical support for the lamp in the associated lighting fixture. Many commercial MR/PAR lamps additionally include a lens or cover glass arranged to receive light directed out of the reflector, a waterproof housing (optionally manufactured of a shatter-resistant material), or other features. Waterproof xe2x80x9csealedxe2x80x9dMR/PAR lamps are especially suitable for outdoor applications or use in other harsh environments.
Commercial MR/PAR lamps exist which are compatible with a wide range of electrical input standards. Some are configured to accept an a.c. line power bus voltage, usually 110V in the United States or 220V in Europe. Low voltage lamps are configured to accept lower voltages, typically 12V d.c. although other voltages such as 6V or 24 V are also commercially used. The low voltage is typically supplied by the 110V or 220V power bus through a low-voltage transformer or other power conditioning apparatus external to the MR/PAR lamp.
Electrical power is typically supplied to the lamp via a standardized electrical base. There are many such xe2x80x9cstandardizedxe2x80x9d bases, however, including threaded (screw-type) connector bases, two-prong (bi-pin) connector bases, bayonet-style connector bases, and the like. Many of these standardized bases are available in a plurality of sizes or detailed configurations. For example, the GU-type connector known to the art comes in a variety of sized and configurations, usually denoted by GU-x where x is a sizing parameter.
In Europe, the most common electrical input standard employs a GU-10 connector configured to receive a 220V a.c. input. In the United States, the most common electrical input standard employs a screw-type connector known as an Edison connector configured to receive a 110V a.c. input. A commonplace low-voltage electrical input standard, sometimes called the xe2x80x9cMRxe2x80x9d standard, employs a GU-5.3 connector configured to receive 12V d.c. In addition to these standardized configurations, however, a wide range of other connector/power configurations are also in more limited use, particularly for specialized applications such as architectural and theatre lighting.
MR/PAR lamps are also increasingly being manufactured with integral electronic controllers, especially for high-end applications such as studio or stage lighting. In one known embodiment, a 12V d.c. MR lamp receives a DMX-512 control signal superimposed on the 12V power input. A DMX controller, embodied by a microprocessor arranged within and integral to the MR lamp, receives the control signal and optionally modifies the lamp operation in response to the received control instructions, for example by changing the lamp intensity or color. Incandescent MR/PAR lamps which include only a single light-generating filament are not individually color-controllable. Hence, the DMX color control is implemented through cooperation of several MR lamps of different colors, e.g. using red, green, and blue spot lights. Other controller interface protocols, such as PDA or CAN, are also known. Instead of using a superimposed a.c. control signal riding on the power input, in other embodiments a radio frequency (rf) receiver is incorporated into the MR/PAR lamp for receiving an rf control signal.
MR/PAR lamps employ a variety of light-generating mechanisms. In addition to incandescent filament lamps, tungsten halogen MR/PAR lamps are popular. In these lamps, a chemical reaction between a halogen gas ambient and a tungsten filament continually returns tungsten sputtered from the filament back onto the filament. In this way, degradation of the light intensity and color characteristics over time are reduced versus ordinary incandescent lamps. MR/PAR lamps employing other types of light generating elements, such as gas discharge tubes, are also known but have gained less commercial acceptance.
In particular, light emitting diode (LED)-based MR/PAR-type lamps are known. LEDs are solid state optoelectronic devices that produce light in response to electrical inputs. LEDs, particularly gallium nitride (GaN) and indium gallium aluminum phosphide (InGaAIP) based LEDs, are being increasingly used for lighting applications because of their durability, safe low-voltage operation, and long operating life. Present LEDs are produces relatively low optical output power, and so LED-based MR/PAR lamps usually include an array of LEDs that collectively act as a single light source. Because most LEDs produce a substantially directed light output, LED-based MR/PAR lamps optionally do not employ a reflector, or employ a reflector that is significantly different from reflectors used in incandescent or halogen MR/PAR lamps.
At the present time, LED-based MR/PAR lamps are not commercially dominant. In part, this is due to significant differences in the electrical input used by the LED arrays as compared with the input associated with conventional incandescent MR/PAR lamps, which can result in a significant portion of the development and manufacturing cost of LED retrofits going toward the power conditioning electronics and the related electrical connectors. To compete commercially, LED-based MR/PAR lamps are advantageously electrically and connectively interchangeable with existing lamp fixtures that are designed to operate with incandescent or halogen MR/PAR lamps.
The difficulty in achieving electrical and connective interchangeability is increased by the wide range of electrical power input standards used in the MR/PAR lamp industry, including voltage inputs ranging from around 6 volts to upwards of 220 volts, voltage inputs of either a.c. or d.c. type, and a wide range of different xe2x80x9cstandardizedxe2x80x9d power connection bases. The trend toward including remote control interfaces employing different communication pathways (rf versus superimposed a.c. line, for example) and different communication protocols (e.g., DMX, PDA, or CAN) further segments the market for LED-based MR/PAR lamps. The diversity of power and communications standards in the MR/PAR lamp industry influences the LED-based MR/PAR lamp manufacturer to produce and maintain a very broad lamp inventory including a large number of different lamp models, an undertaking which is difficult to justify given the present market share of LED-based MR/PAR lamps and the segmented nature of the MR/PAR lamp market in general.
The present invention contemplates an improved apparatus and method that overcomes the above-mentioned limitations and others.
In accordance with one embodiment of the present invention, a lamp is disclosed, including an optical module and an electronics module. The optical module includes a plurality of LEDs for emitting light, and a heat sink thermally coupled to the LEDs. The heat sink has an electrical conduit for transmitting conditioned electrical power to the LEDs. The electronics module includes an input electrical interface adapted to receive input electrical power, and an output coupler rigidly attaching to the optical module for delivering conditioned electrical power to the electrical conduit. The electronics module further includes electrical conditioning circuitry for electrically coupling the input electrical interface to the output coupler.
In accordance with another embodiment of the present invention, an apparatus is disclosed for connecting an associated lamp to an associated electrical power supply. The associated lamp has one or more light emitting diodes (LEDs) and a first coupling element adapted to convey conditioned electrical power to the LEDs. The apparatus includes an input electrical interface adapted to operatively connect to the associated electrical power supply to receive input electrical power and a second coupling element adapted to cooperate with the first coupling element to selectively detachably connect the optical module and the apparatus together. The second coupling element is adapted to electrically connect with the first coupling element to transmit conditioned electrical power to the first coupling element. The apparatus also includes electrical conditioning circuitry connecting the input electrical interface with the second coupling element. The electrical conditioning circuitry converts the input electrical power at the input electrical interface to conditioned electrical power at the second coupling element.
In accordance with another embodiment of the present invention, a light emitting apparatus is disclosed. A heat sink has a first side, a second side, and a conduit connecting the first side and the second side. The second side is adapted to connect with any one of an associated plurality of electrical adaptors each adapted to convert a selected electrical input power to a conditioned output electrical power. The light emitting apparatus also includes a plurality of light emitting diodes disposed at the first side of the heat sink and in thermal communication therewith. The light emitting diodes receive the conditioned electrical power from the selected adaptor via the conduit.
In accordance with yet another embodiment of the present invention, a method is provided for retrofitting a lamp fixture configured to receive an MR- or PAR-type lamp in an electrical receptacle with an LED-based lamp. An LED-based lamp is selected that conforms at least to a diameter of the MR- or PAR-type lamp. A connector module is selected that conforms with the electrical receptacle of the lamp fixture. The selected LED-based lamp and the selected connector module are mechanically joined to form an LED-based retro-fit unit, the mechanical joining effectuating electrical connection therebetween.
In accordance with still yet another embodiment of the present invention, a lamp is disclosed, including an optics module and an electronics module. The optics module includes a plurality of LEDs arranged on a printed circuit board, and a heat sink having a conduit for conveying electrical power through the heat sink. The plurality of LEDs thermally communicate with the heat sink. The electronics module is adapted to convey power to the plurality of LEDs via the electrical conduit of the heat sink. The electronics module has a first end adapted to rigidly connect with the heat sink, and a selected electrical connector arranged on a second end for receiving electrical power. The electronics module further houses circuitry arranged therewithin for adapting the received electrical power to drive the LEDs.
One advantage of the present invention resides in its modular design which allows a single LED-based optics module to connect with a plurality of different power sources. This permits the manufacturer to produce and stock only a single type of optics module that is compatible with a plurality of different power sources.
Another advantage of the present invention resides in its modular design which permits the end user to employ a lamp in different lighting fixtures which use different power receptacles and/or which provide different types of electrical power, by selectively attaching an appropriate electronics module.
Another advantage of the present invention resides in its modular design which permits the manufacturer or end user to select from among a plurality of control protocols such as DMX, CAN, or PDA, for controlling a lamp, by selectively attaching an appropriate power interface which incorporates the selected control protocol.
Yet another advantage of the present invention resides in arranging a heat sink that connects to an LED lighting module on one end thereof, and to an electronics module on an opposite end thereof, to form a unitary lamp with heat sinking of both the LED lighting module and the electronics module.
Numerous advantages and benefits of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description.